1. Field of the Invention
This invention relates to a connector in which countermeasures against vibration are taken, and more particularly to a lever-type connector in which a pair of connector housings are fitted together by pivotally moving a lever.
2. Description of the related art
A connector, used, for example, in the wiring of a vehicle such as an automobile, undergoes vibration developing during the travel of the vehicle, and in some cases contact portions of connection terminals of the connector are worn by such vibration, so that the electrical connection becomes defective. Therefore, there is known a conventional connector in which relative motion between a pair of connector housings, fitted together, is suppressed so as to reduce wear of contact portions of connection terminals which would be caused by the rubbing of these terminals against each other (see, for example, JP-A-2002-198127).
As shown in FIG. 7, the connector 100, disclosed in JP-A-2002-198127, comprises the female connector housing 102 holding the male terminals 103, and the male connector housing 104 receiving the female terminals 101 for electrical connection to the respective male terminals 103. The male connector housing 104 includes an inner housing 106 which holds the female terminals 101, and is fitted into a hood portion 105 of the female connector housing 102, and an outer housing 107 of a generally square tubular shape surrounding an outer periphery of the inner housing 106, the male connector housing 104 being formed into an integral construction.
Limitation projections 108 are formed on an inner peripheral surface of the outer housing 107, and these limitation projections 108 contact an outer peripheral surface of the hood portion 105 of the female connector housing 102 inserted between the outer housing 107 and the inner housing 106. As a result, relative motion of the female and male connector housings 102 and 104 in a direction perpendicular to the direction of fitting of these connector housings is prevented.
However, the limitation projections 108 in the connector 100, disclosed in the above JP-A-2002-198127, could prevent the relative motion between the hood portion 105 of the female connector housing 102 and the outer housing 107 of the male connector housing 104, but could not directly prevent the relative motion between the inner housing 106, holding the female terminals 101, and the female connector housing 102. And besides, the limitation projections 108 could prevent the relative motion of the female and male connector housings 102 and 104 in a direction perpendicular to the fitting direction, but could not prevent the relative motion in the fitting direction. Therefore, there has been a fear that wear of the contact portions of the connection terminals due to the rubbing of these connection terminals can not be sufficiently reduced.
Therefore, the inventors of the present invention have contrived the type of connector in which an outer housing and an inner housing of a male connector housing which are separate from each other are formed, and the inner housing is supported by the outer housing so as to move forward and rearward in a fitting direction, and resilient members, urging the inner housing toward a female connector housing in the fitting direction, are interposed between the inner housing and the outer housing, and inclined surfaces, which are inclined to intersect the fitting direction, and can be mated with each other, are formed respectively on an outer peripheral surface of the inner housing and an inner peripheral surface of a hood portion of the female connector housing in which the inner housing can be fitted.
In the above connector, the inner housing, urged by the resilient members, abuts against the female connector housing. Therefore, the relative motion between the inner housing (holding female terminals) and the female connector housing is directly prevented. Also, the inner housing abuts at the inclined surface (formed at the outer peripheral surface thereof) against the inclined surface formed on the inner peripheral surface of the hood portion of the female connector housing. Since the two inclined surfaces intersect the fitting direction, the relative motion of the inner housing (holding the female terminals) and the female connector housing is prevented both in the fitting direction and in a direction perpendicular to the fitting direction. Therefore, wear of the contact portions of the female and male terminals due to the rubbing of these terminals can be reduced, and therefore a vibration-withstanding performance of the connector is enhanced.
In the above connector, a force, required for fitting the female and male connector housings together, is increased because of provision of the interposed resilient members, and therefore it is preferred to provide a lever for supporting the fitting of the female and male connector housings.
A conventional lever for supporting the fitting of female and male connector housings is pivotally supported on one of the two connector housings, and is engaged with engagement projections formed on the other connector housing, and in this condition the lever is pivotally moved so as to draw the other connector housing, thereby supporting the fitting of the two connector housings. Any lever of this kind functions to reduce an operating force during the fitting operation, using the principle of a lever (leverage).
However, in the conventional lever-type connector provided with such a lever, the lever is supported at its pivot support point, but is free at its portion remote from the support point, and its natural frequency is in a low condition, and is close to a vibration frequency band of a vehicle. Therefore, there is a possibility that this natural frequency coincides with the vibration frequency of the vehicle, so that resonance of the lever occurs, and it is feared that the vibration-withstanding performance of the lever is inadequate. When the two connector housings are disposed in the completely-fitted condition, the lever is usually retained by one of the two connector housings, and therefore is prevented from pivotal movement. However, there is a fear that this retained condition is canceled by the resonance of the lever.
Furthermore, when such a lever is used in the above connector, the resilient forces of the resilient members eventually act so as to disengage the two connector housings from each other, and a load, tending to pivotally move the lever in a direction (returning direction) opposite to the direction of pivotal movement of the lever during the fitting operation of the two connector housings, always acts on the lever through an engagement portion engaged with the female connector housing. Therefore, when the retained condition of the lever is canceled, the lever is instantaneously pivotally moved in the returning direction by the above load. Therefore, when the retained condition of the lever is canceled, for example, by vibration, there is a fear that the resilient forces of the resilient members are greatly reduced, so that the vibration-withstanding performance of the connector is lowered. Furthermore, when the operator inadvertently cancels the retained condition of the lever, there is a fear that the operator hurts his hand.
Also, the limitation projections 108 in the connector 100, disclosed in the above JP-A-2002-198127, could prevent the relative motion of the female and male connector housings 102 and 104 in the direction perpendicular to the fitting direction, but could not prevent the relative motion of these connector housings in the fitting direction. And besides, the limitation projections 108 could prevent the relative motion between the hood portion 105 of the female connector housing 102 and the outer housing 107 of the male connector housing 104, but could not directly prevent the relative motion between the inner housing 106, holding the female terminals 101, and the female connector housing 102. Thus, the vibration-withstanding performance of the connector 100, disclosed in the above Patent Literature 1, was not fully satisfactory.